CyberSecBulletin
CVE-2022-26757NVD status: Modified

watchOS: Use After Free

Published Updated By the CyberSecBulletin desk

CVE-2022-26757 is a high-severity use after free vulnerability in watchOS from Apple, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists versions 8.6, 15.5, 2022 as the first without the flaw, so updating watchOS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 3.12% chance of exploitation within 30 days, higher than 88% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update watchOS to 8.6 or 15.5 or 2022 or 11.6, whichever matches your release line, or a later version.
  2. Update iPadOS to 15.5 or a later version.
  3. Update Iphone OS to 15.5 or a later version.
  4. Read the advisory on support.apple.com for workarounds and exact fixed builds.
  5. Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.

Affected products and versions

VendorProductAffected versionsFixed in
ApplewatchOSbefore 8.6; before 15.5; before 2022; before 11.6; before 12.48.6, 15.5, 2022, 11.6, 12.4
AppleiPadOSbefore 15.515.5
AppleIphone OSbefore 15.515.5
AppleMac OS Xbefore 10.15.7; 10.15.710.15.7
ApplemacOS11.0 up to, but not including, 11.6.6; 12.0 up to, but not including, 12.411.6.6, 12.4
AppletvOSbefore 15.515.5

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
RequiredA user must take an action such as opening a file or link.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighNVD
CVSS 2.09.3HighNVD

Official description

A use after free issue was addressed with improved memory management. This issue is fixed in tvOS 15.5, iOS 15.5 and iPadOS 15.5, Security Update 2022-004 Catalina, watchOS 8.6, macOS Big Sur 11.6.6, macOS Monterey 12.4. An application may be able to execute arbitrary code with kernel privileges.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use After Free

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.

How developers prevent this class of flaw

  • Choose a language that provides automatic memory management.
  • When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.

More Use After Free vulnerabilities (CWE-416)

Timeline

  1. CVE record published.
  2. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in watchOS

All watchOS vulnerabilities

Recent Use After Free vulnerabilities

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